FK506 nerve regeneration research update

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From Glia. 2004 Aug;47(2):120-9.

(FYI, FK506 is an immuneosuppresant drug with nerve regeneration properties -GG)

FK506 enhances regeneration of axons across long peripheral nerve gaps

repaired with collagen guides seeded with allogeneic Schwann cells.

Udina E, FJ, Verdu E, Espejo M, Gold BG, Navarro X.

Department of Cell Biology, Group of Neuroplasticity and Regeneration,

Institute of Neurosciences and Physiology and Immunology, Universitat

Autonoma de Barcelona, Bellaterra, Spain.

We assessed the effects of FK506 administration on regeneration after a

6-mm gap repair with a collagen guide seeded with allogeneic Schwann

cells (SCs) in the mouse sciatic nerve. SCs were isolated from

predegenerated adult sciatic nerves and expanded in culture using a

defined medium, before being seeded in the collagen guide embedded in

Matrigel. Functional reinnervation was evaluated by noninvasive methods

to determine recovery of motor, sensory, and autonomic functions in the

hindpaw over 4 months postoperation. Histological analysis of the

regenerated nerves was performed at the end of the study. Using simple

collagen guides for tubulization repair, treatment with an

immunosuppressant dose of FK506 (5 mg/kg/day) resulted in significant

improvement of the onset and the degree of reinnervation. While the

introduction of allogeneic SCs did not improve regeneration versus a

collagen guide filled only with Matrigel, treatment with FK506 allowed

for successful regeneration in all the mice and for significant

improvement in the levels of functional recovery. Compared with the

untreated group, there was greater survival of transplanted pre-labeled

SCs in the FK506-treated animals. Morphologically, the best nerve

regeneration (in terms of nerve caliber and numbers of myelinated axons)

was obtained with SC-seeded guides from FK506-treated animals. Thus,

FK506 should be considered as adjunct therapy for various types of

tubulization repair.